#pragma ident "$Id:$"

/**
 * @file CNavDataElement.hpp
 *  This class encapsulates the "least common denominator"
 *  for non orbit/clock data defined in the CNAV and CNAV-2
 *  sections of the GPS signal interface specifications.
 *  This includes items such as the group delay, ISC, UTC, IONO,
 *  EOP, GGTO, and text information.  The items in common across these
 *  data sets are unified here.  This includes the concept of an
 *  epoch time, a transmit time, a source SV, and a source
 *  carrier/code.
 *
 *  This is a pure virtual class.   Each of the data elements are
 *  fully implemented (including load methods) in descendent
 *  classes.  The use of a common base class makes it practical to
 *  store the elements together in larger stores while maintaining
 *  the characteristics of the individual data types.
 */

#ifndef GPSTK_CNAVDATAELEMENT_HPP
#define GPSTK_CNAVDATAELEMENT_HPP

//============================================================================
//
//  This file is part of GPSTk, the GPS Toolkit.
//
//  The GPSTk is free software; you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published
//  by the Free Software Foundation; either version 2.1 of the License, or
//  any later version.
//
//  The GPSTk is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with GPSTk; if not, write to the Free Software Foundation,
//  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
//
//  Copyright 2013, The University of Texas at Austin
//
//============================================================================

//============================================================================
//
//This software developed by Applied Research Laboratories at the University of
//Texas at Austin, under contract to an agency or agencies within the U.S.
//Department of Defense. The U.S. Government retains all rights to use,
//duplicate, distribute, disclose, or release this software.
//
//Pursuant to DoD Directive 523024
//
// DISTRIBUTION STATEMENT A: This software has been approved for public
//                           release, distribution is unlimited.
//
//=============================================================================


#include "ObsID.hpp"
#include "Exception.hpp"
#include "CommonTime.hpp"
#include "GNSSconstants.hpp"
#include "SatID.hpp"
#include "GPSWeekSecond.hpp"

namespace gpstk
{
class CNavDataElement
{
public:
    /// Constructors
    /// Default constuctor
    CNavDataElement( );

    /// Destructor
    virtual ~CNavDataElement() { }

    /// Clone method.
    /// Return pointer to new copy of this type.
    /// Implication of the "= 0" at this end is that this is a
    /// "pure virtual" method and that makes CNavDataElement an abstract
    /// class.  That is to say no objects of type CNavDataElement may
    /// be constructed.   This is a good thing since CNavDataElement
    /// doesn't even provide methods to load its' members.
    /// Only its' descendents may be instantiated.
    virtual CNavDataElement* clone() const = 0;

    /**
         *   Return true if data have been loaded.
         *   Returns false if the object has been instantiated,
         *   but no data have been loaded.
         */
    virtual bool dataLoaded( ) const;

    virtual std::string getName() const = 0;

    virtual std::string getNameLong() const = 0;

    // Returns true if this two objects are
    //   a.) same concrete type, and
    //   b.) same data contents.
    // This is intended as a "data uniqueness test" to allow
    // detection of successive transmissions of same data
    // and avoid duplicate storage.  The exact rules for
    // uniqueness will vary by descendent class.
    virtual bool isSameData(const CNavDataElement* right) const = 0;

    /** Output the contents of this orbit data to the given stream.
     * @throw Invalid Request if the required data has not been stored.
     */
    static void shortcut(std::ostream & os, const long HOW);

    static void timeDisplay(std::ostream & os, const CommonTime& t);
    /*
          virtual void dumpTerse(std::ostream& s = std::cout) const
             throw( InvalidRequest ) = 0;
    */
    virtual void dumpHeader(std::ostream& s = std::cout) const
    throw( InvalidRequest );

    virtual void dumpBody(std::ostream& s = std::cout) const
    throw( InvalidRequest );

    virtual void dumpFooter(std::ostream& s = std::cout) const
    throw( InvalidRequest );

    virtual void dump(std::ostream& s = std::cout) const
    throw( InvalidRequest );

    /// Overhead information
    //@{
    bool    dataLoadedFlag;  /**< True if data is present, False otherwise */
    SatID   satID;	          /**< Define satellite system and specific SV
                                    that transmitted the data */
    ObsID   obsID;           /**< Defines carrier and tracking code */
    CommonTime ctEpoch;      /**< Epoch time                        */
    CommonTime ctXmit;       /**< Time of transmission              */
    //@}

}; // end class CNavDataElement

//@}

std::ostream& operator<<(std::ostream& s,
                         const CNavDataElement& eph);

} // end namespace

#endif // GPSTK_CNavDataElement_HPP
